Subject: Re: port bio(4) and bioctl(8) from openbsd ?
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Juan RP <juan@xtrarom.org>
List: tech-kern
Date: 04/07/2007 20:06:54
On Sat, 7 Apr 2007 19:07:19 +0200
Manuel Bouyer <bouyer@antioche.eu.org> wrote:

> Hi,
> do we want to port the bio(4) interface and associated bioctl(8) tool
> from openbsd ? Basically it allows control of hardware RAID controllers in a
> generic way (get states, add hot-spare, start rebuilds, etc ...).
> On OpenBSD it's currently supported on ami(4), arc(4), ciss(4), mfi(4).
> I won't go into the softraid stuff, at last not yet.
> Man pages:
> http://www.openbsd.org/cgi-bin/cvsweb/~checkout~/src/sbin/bioctl/bioctl.8?rev=1.43&content-type=text/plain
> http://www.openbsd.org/cgi-bin/cvsweb/~checkout~/src/share/man/man4/bio.4?rev=1.19&content-type=text/plain
> 
> In kernel, there's a pseudo-device (bio) to which RAID controllers registers
> (note that we can use the controllers without bio(4) in the kernel).
> This pseudo-device keeps a list of raid controllers, and dispatch the
> IOCTLs. This avoids having one major device per controller driver type.
> 
> OpenBSD has added sensors for the drives: SENSOR_DRIVE, with the states:
> #define SENSOR_DRIVE_EMPTY    1
> #define SENSOR_DRIVE_READY    2
> #define SENSOR_DRIVE_POWERUP  3
> #define SENSOR_DRIVE_ONLINE   4
> #define SENSOR_DRIVE_IDLE     5
> #define SENSOR_DRIVE_ACTIVE   6
> #define SENSOR_DRIVE_REBUILD  7
> #define SENSOR_DRIVE_POWERDOWN        8
> #define SENSOR_DRIVE_FAIL     9
> #define SENSOR_DRIVE_PFAIL    10
> The benefit of this is that we could get notification in real time
> instead of polling though bioctl.
> 
> I want this for mfi(4), for which I have no alternatives to get RAID status
> (if a drive fail you don't know, unless you go in front of the box and look
> at the LEDs). I will also add support to amr(4) as I have the hardware
> for this.

IMHO it's good to have.

-- 
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